Process for dyeing polyamide fibers

ABSTRACT

WHEREIN R is an alkyl radical having from four to 18 carbon atoms and M is either an alkali metal, alkaline earth metal, ammonium, or a substituted ammonium radical.   A process for producing barre free dyeing of polyamide fibers comprising dyeing said fibers with a composition comprising an acid dye and a dialkyl sulfosuccinate having the following formula:

United States Patent [72] Inventor Anthony De Maria Easton. Pa.

[21] Appl. No. 787.204

[22 Filed Dec. 26, I968 [45] Patented Nov. 9.1971

173] Assignee GAF Corporation New York. N.Y.

154] PROCESS FOR DYEING POLYAMIDE FIBERS 6 Claims, No Drawings [52] U.S. Cl 8/173. 8/178 [51] Int. Cl D06p 5/04 [50] Field oiSearch 8/173, 178. 89; 260/481 [56} References Cited UNITED STATES PATENTS 2,028.091 1/1936 .laeger 260/481 2.176.423 10/1939 Jaeger 260/481 2.558.733 7/1951 Cresswell et a1. 8/177 FOREIGN PATENTS 802.574 10/1958 Great Britain 8/65 Primary linunrlwr-George F. Lesmes Axxixmnl Eruminer-T. 1. Herbert. Jr. Arlurnc t'.r-Walter C. Kihm and Samson B. Leavitt H C-COOR MOiSCIICOOR wherein R is an alkyl radical having from four to 18 carbon atoms and M is either an alkali metal, alkaline earth metal. ammonium. or a substituted ammonium radical.

PROCESS FOR DYEING POLYAMIDE FIBERS The instant invention is directed to a process of uniformly dyeing polyamide fibers.

1n the past the commercial practice of dyeing the synthetic linear polycarbonamides more familiarly known as nylon has been carried out by means of dispersed or acetate dyestuffs. These dispersed dyestuffs have great covering power for nylon yarns and are not highly sensitive to the normal variations found in such yarns. However, the dispersed or acetate colors lack fastness to light and to washing. in contrast, the anionic dyestuffs best exemplified by the class of acid dyes have extremely good fastness on nylon to both light and washing. It has not been commercially feasible to utilize the anionic dyestuffs in the majority of nylon filament dyeings, however, since those dyestuffs are extremely sensitive to variations between different fibers and different parts of the same fibers. Nylon yarns which have been spun at different times or from different lots of polymer demonstrate these variations most clearly. Frequently yarns spun at different times are dyed to different shades with the anionic dyestuffs when dyed by standard dyeing procedures. As a result the nylon fabrics dyed with anionic dyes are often colored in an uneven fashion, showing streaks and shade depth variations in knitted goods, and barre effects, warp streaks and the like inwoven goods. The inability to secure even dyeing of nylon yarns and fabrics is believed to be due to slight variations in the physical structure of the parent polymers such as variations in orientation due to the drawing to which each filament is subjected. Other factors occurring in the spinning and processing of the yarn, the mechanical action of the textile machinery used in the knitting or weaving of the fabrics, and perhaps other causes as well, also affect the even dyeing of nylon yarns and fabrics. This inability to evenly dye nylon yarns and fabrics with the anionic dyestuffs has curtailed the large scale use of such dyestuffs for dyeing the nylon materials on which they exhibit excellent light and wash fastness properties.

ln addition, many explanations have been offered to explain the barre phenomenon, none of which has been completely satisfactory. However, it is known that both the drawing of the polymer filament and the heat history of the filament itself are responsible for the apparent lack of uniformity in the final dyeing. The drawing of the polymer filament is a necessary step to the full development of the desirable physical properties of the fiber, such as strength and elasticity. During the drawing the polymer molecules become highly oriented, therefore creating the possibility and conditions for the formation of groups of chain ends alternating with or following highly crystalline areas of packed parallel molecules. Since it has been theorized that the terminal amino groups of the polymer chains are the more important and more readily accessible sites to the dye, it is easily seen why the uniformity of dyeing would be impaired by the drawing of the polymer fila ment.

With regard to the heat history of the filament, it can be said that heat affects the polymer structure of the filament at each processing step. Exposure to heat results in an increase in the crystallinity of the polymer along with additional molecular rearrangement phenomena such as chain dislocation etc. The extent of these changes is influenced by the temperature reached and by the moisture present.

Numerous dyeing systems have been developed in an attempt to overcome the lack of levelness and uniformity associated with the use of acid dyes. These systems have included cationic agents which tend to complex the acid dye and release it gradually so as to retard the dyestuff strike, and the use of colorless anions designed to compete with the dye for the fiber dye sites so as to retard the dyestuff.

All of these systems, however, are suited to only a small number ofdyes and and become limited by their own selectivity in this respect.

Therefore, it is an object of the instant invention to provide a dyeing system for polycarbonamides which produces a level, uniform, and barre free dyeing effect and which employs a large number of different dyestuffs.

Yet a further object of the instant invention is to provide a dyeing system which produces a ham: free dyeing effect on polycarbonamides, said system comprising a sulfonated dialkyl succinic acid and an acid dyestuff.

As used in the instant specification the term levelness" is meant to refer to a dyeing, the results of which are an evenly dyed appearance of a fabric or yarn. Poor levelness shows up in streaks or areas of light and dark color which have been unevenly dyed. This can be attributed to sharp variations in the temperature of the dye bath, too fast a rate of temperature increase, or other mechanical interferences such as poor agitation or uneven distribution of the fabric in the dye bath. The term barr is meant to refer to defective dyeing uniformity, caused, as we have previously discussed, by both the drawing of the polymer filament and the heat history of the filament itself. Therefore, while levelness is caused by factors affecting the process of dyeing, the potential for barre defects is inherent in the fiber.

With the instant invention, polycarbonamides are dyed with a level, barre free effect with a dialkyl sulfosuccinate salt and an acid dye. The useful sulfonated dialkyl succinatc salts include those salts with from 12 to 40 carbon atoms such as:

bis(butyl) sulfosuccinate bis(amyl) sulfosuccinate [bis(pentyl) sulfosuccinate] bis(hexyl) sulfosuccinate bis(heptyl) sulfosuccinate bis(octyl) sulfosuccinate bis(nonyl) sulfosuccinate bis(decyl) sulfosuccinate bis(undecyl) sulfosuccinate bis(dodecyl) sulfosuccinate bis(tridecyl) sulfosuccinate bis(tetradecyl) sulfosuccinate bis(pentadecyl) sulfosuccinate bis(hexadecyl) sulfosuccinate bis(heptadecyl) sulfosuccinate bis(octadecyl) sulfosuccinate More particularly, these salts include but are not limited to alkali metal, i.e., lithium, potassium, sodium, alkaline earth metal, ammonium and substituted ammonium, salts, or any other water soluble salts of dialkyl sulfosuccinates.

bis( 1,2-dimethyl-hexyl) sulfosuccinate bis(2,6-dimethyl-heptyl-4) sulfosuccinate bis( 1,4-dimethyl-heptyb4) sulfosuccinate bis( l,4-dimethyl-heptyl-3) sulfosuccinate bis( 1,4-diethyl-heptyl) sulfosuccinate bis( l,3-diis0propyl butyl) sulfosuccinate bis( 3,5-dimethyl-octyl-5) sulfosuccinate bis( l,7-diethyl tetradecyll O) sulfosuccinate bis( 1,3-dimethyl butyl-l sulfosuccinate bis(3,8-dibutyl heptyl-S) sulfosuccinate bis( 1.7-diphenyl octyl-4) sulfosuccinate, etc.

The above dialkyl sulfosuccinates are all old and wellknown in the art. They may be prepared according to the methods disclosed in US. Patents 2,028,091 and 2,175,423 or by any other conventional method. These compounds generally correspond to the following formula:

HgC-COOR M0 8 I COOR wherein R represents an alkyl radical having from four to 18 carbon atoms, and M represents either an alkali metal. alkaline earth metal, ammonium, or substituted ammonium radical.

The sulfonated dialkyl succinates assist in producing level, barre free dyeings when they are employed at the beginning of the dye cycle in amounts of from 0.1 percent to 10 percent and preferably in amounts of from 0.l to 6 percent. The percentages are based on the weight of the goods or fibers to be dyed. The amounts required are higher for lighter shades as a lower percentage of dye is employed and lower for darker shades in which higher percentages of dyes are employed. Therefore, in general when one employs from 0.05 percent to 1 percent (OWF) of dye, said amounts based on the weight of the goods, one would use about 4 percent (OWF) of the sulfosuccinate. When 1 percent to 2 percent (OWF) of dye is employed, one would use about 2 percent (OWF) of the succinate, and about l percent (OWF) of the succinate would be employed when about 2-4 percent (OWF) of the dye is employed. The sulfonated dialkyl succinates can also be added at various stages during the dyeing process or they may be used to repair defective dyeings. The useful sulfonated dialkyl succinates have a retarding action on the dyestuff exhaustion and definitely affect mobility of the dye by increasing its migration and transfer properties.

The useful acid and direct dyes which may be employed in connection with the instant invention include water-soluble nonmetallized acid dyes of various groups such as monoazo, diazo, anthraquinone, etc. These dyes are preferably nonmetallized complex containing acid dyes and include, but are not limited to Cl. Name C.l. Number Milling Yellow Acid Yellow 38 25135 Supranol Yellow GGA Acid Yellow 40 18950 Fast Light Yellow GGXN Acid Yellow 17 18965 Wool Fast Orange GA Mordant Orange 6 26520 Supranol Orange RA Acid Orange 45 22l95 Supranol Red RL Acid Red 99 23285 Supranol Red PG Acid Red 85 22245 Suprunol Brilliant Red BA Acid Red I33 l7995 Supranol Red PBX Acid Red l l4 23635 Alizarine Supra Blue A Acid Blue 25 62055 Phenamine Scarlet B Direct Red 37 22240 Chrysophcnine Y Direct Yellow l2 24895 Supra Light Rubine BLA Acid Red 32 17065 Alizarine Astrol 8 Acid Blue 27 61530 Alizarine Sky Blue BS Acid Blue 78 62l05 Alizarine Supra Sky RA Acid Blue 62 62045 Alizarine Cyanine Green GHN Acid Green 25 6l570 Alizarine Cyanine Green GWA Acid Green 44 M590 Sulphon Cyanine SRA Acid Blue l l3 26360 Sulphon Cyaninc GRA Acid Blue I 26400 Sulphon Cyanine GA Acid Blue ll8 264l0 Anthraquinone Violet D Acid Violet 34 61710 Alizarine Fast Gray BLN Acid Black 48 65005 The dye system of the instant invention is operable at a broad range of pH's with the preferred range being a pH of from 3 to 7. Furthermore, the system may be employed at various temperatures and satisfactory dyeings are obtained even below the boil. The preferred temperature range, however, is from about 160 to about 230 F. In this regard, it is of note that when one employs the novel process of the instant invention, one is able to carry out dyeing procedures at lower temperatures than those conventionally employed in such processes.

In addition to the production of level and barre free dyeings in the coloring of other types of nylon materials, the instant system is also useful in connection with the dyeing of nylon carpetings. In the past, when nylon carpetings having a jute backing were dyed, the nylon become stained as a result of the natural coloring matter bleeding off the jute in the dye bath. lts concentration in the dye bath increases as the dyeing progresses. and the nylon which has a pronounced affinity for this brown-colored matter picks it up readily. The resulting brown coloration which has a very low-light fastness, adversely affects the fastness and the purity of the final shade. The use of dialkyl sulfosuccinates in the dyeing of jute-backed nylon carpets prevents the brown matter coming off the jute backing from affecting the final shade of the nylon surface.

In addition, it has also been found that the useful dialkyl sulfosuccinates can be employed to repair barre dyeings. These sulfosuccinates as noted previously increase the migrating, the mobility and transfer properties of acid nonmetallized dyes. in general, the goods can be heated in a bath with the dialkyl sulfosuccinate to about 90-l20 F. An alkaline pH is established so as to encourage the migration of the dye off the fiber. Any suitable alkaline material may be employed such as ammonium hydroxide. The bath can be taken to the boil or close thereto over about 30 minutes and maintained there for at least about 45 minutes. At this point, a great deal of dye has been transferred from the fabric to the dye bath. To return this dye to the fiber in the presence of the barr suppressant which we have in the bath, a gradual addition of prediluted acetic acid can be made (about 2 percent OWF.) to bring about satisfactory exhaustion of the dye bath. The resulting dyeing, assuming that suitable dyestuffs have been used, should be barre free. If additional dyestuff is required for shade adjustment, it may be added at any time before the acetic acid additions.

The novel process of the instant invention can be employed in connection with numerous forms of polycarbonamide fibers, including but not limited to woven, felted, filament, staple fiber, yarn, slubbing, wound packages, etc.

The present invention will now be described by reference to the following specific examples. Such examples are presented for purposes of illustration only, and the present invention is in no way to be deemed as limited thereto.

EXAMPLE 1 Comparative dyeings were made of i0 gram samples of texturized nylon 66 (Banlon, Joseph Bancroft & Company) using dye baths comprising:

A. 0.2 percent OWF Dye plug l percent ethoxylated nonionic surfactant comprising nonyl phenol+30 mols E.O., 75 percent active and 6 percent ammonium sulfate. (E.O. means ethylene oxide.)

B. 0.2 percent OWF Dye plus 4 percent Sodium bis-(2,6-

dimethyl-heptyl-4)sulfosuccinate. The baths were established at a ratio of 1 gram of fabric to 40 cos. liquid, and the temperature raised to the boil over a period of 45 minutes, after the first 30 minutes of which I percent acetic acid (56 percent) was added to the bath (A). The dye baths were maintained at this temperature for a period of l hour, and the samples were subsequently rinsed and dried. They were also critically examined for levelness and barr. The dyeings were tested for light fastness according to the AATCC Standard Method l6A-l964. A rating scale of l to 5 was used in which 5 indicates a level or barr free dyeing and l a dyt aing showing an unlevelness or a pronounced degree of barre.

As may be seen from table I, there was a dramatic improvement in both levelness and barre effect when sodium bis-(2,6- dimethyl-heptyl-4)sulfosuccinate was employed in the dye bath.

TABLE I Improvement in- Levelness Barre Lightiastness Employing dye bath A B A B A B Milling Yellow 0 (Acid Yellow 38-01. 25135) 2 5 2 45 6 6 Su ranol Yellow GGA (Acid Y low 40-01. 18950) 4 5 4-5 4-5 3-4 5 Fast Light Yellow GGXN (Acid Yellow 17-C.I. 18965) 4 4 3-4 4 4 4 W001 Fast Orange GA (Mordant Orange 6-0.1. 26520) 4 4 3-4 4-5 6 6 Supranol Orange RA (Acid Orange 45-01. 22195) 1 3 l 2 Supranol Red BL (Acid Red 99-01. 23285) 3 4-5 2 4-5 5 5 Supranol Red PG (Acid Red -01. 22245) 2 4 2 4 5 5 Sopranol Brilliant Red BA (Acid Red 133-01. 17995) 2 3 1-2 3 l Supranol Red PBX (Acid Red 114-01. 23635) 2 3 1-2 2 improvement ln- IAVtElllESS Barr Llghtfnstness Employing dyo bath. A B A B A l! Supra Light ltubinv liLA (Acid Red 32(7.l. 17065) 3 4-5 2 4-5 5 G Alizarine Sky Blue BS (Acid (Blue IS-(.I. 02105) 4 4-5 34 4*5 t) h Alizarilu- Supra Sky RA (Acld Blue 62C.l. 62045) 3 4 2 4 5 h Allzarinu Cyanino Green (ilIN (Acid Green 25C.I. 6l500),, '2 4 1 4-5 6 6 Aliizarine Cyanine Green (ill'A (Acid Green 44C.I. 61590) 3 4-5 3 4-5 6 6 Sulphon Cyanine 5 RA (Acid Blue 113C.I.26360)... l 3 1 3 Sulphon Cyanine GRA (Acid Blue 120C.I. 264 0) 1 l l 2 Sulphon Cyauine GA (Acid Blue 118C.l. 26410) l Palatine Black WANA (Acid Black 52-01. 15711) Supranol Red RA (Mixture of C.I. Acid Red l14-C.I. 23635 and C.I. Acid Red 85-22245) 2 3 l-2 2 Supranol Brilliant Red 30 (Acid Red l55C.I. l8130). 4-5 2 4-5 3-4 3-4 Supranol Blue GG (Acid Blue Alizarine Green 50 (Acid Green 4C.I. 62560) 2 4-5 2 4 5-6 0 EXAMPLE ll Comparative dyeings were made of IO gram samples oftaffeta (nontexturized nylon 66 filaments). The fabric was rolled and introduced in the stainless steel wire baskets available on the Vistamatic (Ahiba) automatic dyeing equipment. The dye baths comprised:

a. 0.2 percent ofDye OWF b. 0.2 percent OWF Dye and 4 percent sodium bis(2.6-

dimethyl-heptyl-4)sulfosuccinate.

The baths were established at a ratio of 1 gram of fabric to 40 cc. of liquid and the temperature raised to 200 F.. over a period of 45 minutes. After the first 30 minutes at this temperature 1 percent of acetic acid (56 percent) was added to both (a) and (b). The dyeings were maintained at 200 F.. for 30 minutes longer and the samples were subsequently rinsed and dried.

The dyeings were rated for levelness and barre as in example I. As may be seen from table ii there was a dramatic improvement in both levelness and barre when sodium bis(2.6- dimethyl-heptyl-4) sulfosuccinate was employed in the dye bath.

TABLE ll lmprmement in Luelness Barn: in) (h) (a) (h) Milling Yellon (Acid Yellnn 38) (Cl. 25 l 35) 2 5 3 5 Wool Fast Orange GA (Mordant Orange (C.I. 16520) 2 5 1 5 Suprunol Red PG Extra (Acid Red 85) (C.I. 22245) i 2 4-5 4 Supranol Red RL (Acid Red 99) (CL 23285] 2 4-5 2 4-5 Supranol Light Ruhine BLA (Acid Red (C.I. W065) 3 5 3 4-5 Alizarine Astrnl B (Acid Blue 27) (C.I.(IISJO) Z 3 5 4-5 Alizarine Sky Blue 85 (Acid Blue 78) (C.I. 62105) 3-4 5 3-4 4-5 Alizarine Supra Sky RA (Acid Blue 62) (C.I. 62045) 4 5 3-4 5 Alizarine Cyanine Green GHN (Acid Green 25) (C.I. M570) 2 4-5 2 4-5 EXAMPLE lll Texturized nylon (nylon 66-Banlon. Joseph Bancroft & Company) was added at room temperature to three groups of dye baths, each comprising: for Group I: 0.2 percent Dye-OWF The temperature of these dye baths were raised to 190 F., for 30 minutes. l0 percent common salt was then added and the dyeing continued at l F.. for 45 additional minutes. The dyeings were then rinsed and dried. for Group 2: 0.2 percent Dye-OWF The dyeings in this group were handled exactly as in group i except for the temperature which was maintained at the boil. for Group 3: 0.2 percent Dye-OWF 4.0 percent OWF Sodium bis-(2,6-dimethyl-heptyl-4) sulfosuccinate. The temperature of these dye baths were raised to F.. and held at 190 F., for 30 minutes. I percent acetic acid (56 percent) was then added and the dye bath maintained at 190 F., for 30 minutes longer. The fabric was then rinsed and dried. Table III lists barre and lightfastness ratings for each group of dyeings according to the rules set forth in example I. As can be noted from table I". the use of the sulfosuccinate in the dye bath has resulted in practically barr'e free dyeings at temperatures considerably below the boil which also show a lightfastness superior to that of the dyeings in group I and 2. The dyes employed correspond to the following formulas.

ANQANQ EXAMPLE V EXAMPLE Vl Ten gram samples of tiger cloth were added to a dye bath 1 comprising 0.2 percent Dye and 4 percent Sodium bis-(2.6- dimethyl-heptyl-4) sulfosuccinate. The temperature of this dye bath was raised to the boil over a period of minutes and l percent acetic acid was then added. The temperature of the dye bath was maintained for an additional 45 minutes. As may be seen from table V. the resulting dyeings were free from the barre effect.

TABLE III Group I Group II Group III Dye (corresponding to structure number) Percent Barre Lighltastness Barr Lightlastness Burr Lightlastness EXAMPLE lV TABLE V Texturized nylon (nylon 66 Banlon. Joseph Bancroft & Company) was added at room temperature to three groups of Bang dye baths prepared and handled exactly as in example ill for m Sodium the use of 0.5 percent OWF of dye in each. -dimeth \-l -heptyl--H Table IV in addition to listing barre and lightfastness ratings F S I I f h (Same as 10 4 Salt after i; Acetic acidfor each group ofdyemgs according to the rules set ort in ex- Table Firs m min rm 3 mm ample I. also gives ratings for the degree ofdye exhaustion. The degree of exhaustion rating was obtained in the follow- (Ex. v) (Ex. VD mg manner. 3 5 After the dyeings were removed the dye baths were strongly I! 3 s acidified by the addition of2 percent OWF of formic acid (90 3' 2 percent). Undyed nylon 66 skeins of equal weight to the samv 3 4 ples dyed were immersed in the bath so prepared and run at w 3 4 the boil for 45 minutes. After rinsing and drying these skeins 1 "1- the depth ofdyc ing was compared to that of the original dye- Murine Supra ings estimating in this fashion the percent of dye removed mut- A 1-4 s from the dye bath by the original dyeing.

it e v i xam e ill nd T rble IV confirms the resu s obs r ed n e pl :1 in EXAMPLE v" addition. shows that the use of the sulfosuccinate followed by lowering of the pH of the dye bath has resulted in as good a degree ofexhaustion of the dyestuff from the baths as that obtained in the dyeings without additive (group l and 2).

Twenty gram samples of nylon 6 carpet (Allied Chemical Corporation) were dyed in dye baths comprising: g a. 0.2 percent OWF Celliton Fast Blue FFRN (Dispersel TABLE IV Group 1 Group 2 Group 3 Estimated Estimated Estimated Per- Lightpercent; Lightpercent Lightpercent Dyt cent Barri'astness exhaustion Barr iastness exhaustion Barre tastness exhaustion IL 0. 5 4 5-6 98 4 5-6 95 4-5 6 98 III 0. 5 4-5 G 90 4-5 6 5 6 95 1 V. 0. 5 4 6 98 4 7 95 4-5 6-7 98 VII. 0. 5 4 6-7 95 4 6 4-5 a VIII. 0. 5 3 6 98 3 6 95 4 7 98 Alizariue Sup 0.5 4 5-6 90 4 5-6 80 4-5 6 90 Blue 3-C I. No. M505); 4 percent OWF Sodium bis-(2.6- dimethyl-heptyl-4 sulfosuccinate h. 0.2 percent OWF Celliton Fast Blue FFRN (Disperse Blue .l-(.'.l. No. 6l505). The ratio of carpet to water was I gram of carpet to 40 ccs. of water. The temperature of both baths was raised to the boil in 45 minutes and maintained there for a period of 1 hour. The samples were rinsed and water extracted in a centrifuge and the samples subsequently dried. The nylon sample from bath (a) showed a brilliant blue shade, while the sample from bath (b) was considerably greener and duller. The samples were subsequently exposed to the (Fade-o-Meter) carbon are light source for hours and sample (a) exhibited little fading. while sample (b) demonstrated a dramatic loss to yellow-green cast.

EXAMPLE Vlll Samples of nylon 6 carpet (Allied Chemical Corporation) were dyed in dye baths having the following composition:

a. 0.2 percent Supra Light Rubine BLA (Acid Red 32C.|. No. l7065) b. 0.2 percent Supra Light Rubine BLA 4 percent Sodium bis-( 2,6 dimethyl-heptyl-4) sulfosuccinate c. 0.2 percent Alizarine Fast Gray BLN (Acid Black 48C.l. No. 65005) d. 0.2 percent Alizarine Fast Gray BLN 4 percent Sodium bis(2,6-dimethyl-heptyl-4) sulfosuccinate.

All the dye baths were raised to the boil over a period of 45 minutes. After the first minutes 1 percent acetic acid (56 percent) was added to each of the dye baths to complete the exhaustion of the dyes from the bath. Sample (a) showed an uneven dyeing result due to barre and not to a lack of levelness, and the color was altered by lignin to a brick red color. Sample (b) showed an improved dyeing result and the barre effect was greatly reduced and the true shade of the Rubine dye was unaltered by lignin. Sample (c) resulted in an uneven dyeing due to barre and a greenish-gray shade of color, while sample (d) showed a much more uniform dyeing and a considerable reduction in ham: and the true blue shade characteristic of the dye was apparent.

EXAMPLE lX Comparative dyeings were made of 10 gram samples of nylon 66, nylon 6, nylon l l, nylon 6l0, nylon 6 /6, Perlon and Rilsan, using dyes particularly comprising those in table I:

a. 0.2 percent OWF Dye plug l percent ethoxylated nonionic surfactant comprising nonyl phenol 30 mols E.O., 75 percent active and 6 percent ammonium sulfate.

b. 0.2 percent OWF Dye plus 4 percent Sodium bis-(2,6- dimethyl-heptyl-4) sulfosuccinate.

in each instance there was a dramatic improvement both in levelness and ban effect when sodium bis-(2,6-dimethyl-heptyl-4) sulfosuccinate was employed in the dye bath, as per the procedure in example 1.

EXAMPLE X Comparative dyeings were made of 10 gram samples of texturized nylon 66 using dye baths comprising those in table l:

EXAMPLE XI The procedure ofexamples IX and X were repeated except that the particular sulfosuccinates employed were bis( l.4- diethyl-heptyl) sulfosuccinate, bis( l.3-diisopropyl butyl) sulfosuccinate. bis(3,5-dimcthyl-octyl-5) sulfosuccinate. bis( l.7- diethyl tetradecyl-lO) sulfosuccinate. bis( l,3-dimcthyl butyll l sulfosuccinate, bis(3,8-butyl heptyl-S) sulfosuccinate. and bis( l 7-diphenyl octyl-4) sulfosuccinate, etc. In each instance there was a dramatic improvement in both levelness and barre effect when the sulfosuccinate was employed as compared to the process when said sulfosuccinate was not employed.

In the preceding examples the term nylon relates to the polyamide fiber obtained by condensing adipic acid with hexamethylenediamine, nylon 610" denotes the polyamide fiber obtained by condensing sebacic acid with hexamcthylenediamine, nylon 66/6" is the polyamide copolymer obtained by condensing together adipic acid, hexamethylenediamine and caprolactam, Perlon is the polyamide fiber obtained from caprolactam and Rilsan that ob tained from waminoundecylic acid.

Furthermore, in the preceding examples and throughout the specification. all indicated percentages are based on the weight ofthe fibrous goods employed as indicated by OWF.

As noted in the above examples and throughout the specification there may be added an acid such as acetic acid toward the end of the dyeing process to complete the exhaustion of the dyestuffs. Furthermore, as previously noted the acidification may also be employed for similar purposes wherein barre dyeings are repaired by subsequent treatment. Preferably, acetic acid is employed in those processes which require acidification. In addition, however, other organic or inorganic acids can also be employed in the known manner, such acids including formic acid, acetic acid, hydrochloric acid, sulfuric acid, phosphoric, alkyl and aryl sulfonic acids, and their acidic salts such as ammonium sulfate and the like.

In addition, as previously noted some of the dyeing processes are operative after an initial treatment with alkalizing materials. Those alkalizing materials which may be employed include but are not limited to ammonium hydroxide and alkali metal salts of weak acids such as sodium acetate and the like.

What is claimed is:

l. A method of producing improved polycarbonamide fibrous dyeings consisting essentially of treating polycarbonamide fibrous material with an aqueous medium comprising from 0.ll0 percent by weight based on the weight of the fibrous material of a water-soluble salt of a dialkyl sulfosuccinate containing from about l2 to about 40 carbon atoms, in

the presence of an acid dye.

2. The method of claim I wherein the dialkyl sulfosuccinate is a bis-nonyl sulfosuccinate.

3. The method of claim 1 fosuccinate is sodium bis-( cinate.

4. The process of claim 1 wherein the pH of the dye bath is about 3 to about 7.

S. The process of claim 2 wherein the pH of the dye bath is wherein the salt of a dialkyl sula. 0.2 percent OWF Dye plus 1 percent ethoxylated abol-"houbom nonionic surfactant comprising nylon phenol 30 mols E.O., 75 percent active and 6 percent ammonium sulfate.

b. 0.2 percent OWF Dye plus 4 percent Sodium bis-(2,6-

, dimethyl-heptyl-4) sulfosuccinate.

6. The process of claim 3 wherein the pH of the dye bath is about 3 to about 7.

2,6-dimethyl-heptyl-4) sulfosuc- 

2. The method of claim 1 wherein the dialkyl sulfosuccinate is a bis-nonyl sulfosuccinate.
 3. The method of claim 1 wherein the salt of a dialkyl sulfosuccinate is sodium bis-(2,6-dimethyl-heptyl-4) sulfosuccinate.
 4. The process of claim 1 wherein the pH of the dye bath is about 3 to about
 7. 5. The process of claim 2 wherein the pH of the dye bath is about 3 to about
 7. 6. The process of claim 3 wherein the pH of the dye bath is about 3 to about
 7. 